I have a parent and I add a child to it. After that I append <br> to the parent's innerHTML, but after that the child's innerHTML can't be changed anymore. What's going on here? Why isn't the final result "bbb"?

But if you comment out container.innerHTML += "<br>", it does change to "bbb".

let container = document.createElement('div')
document.body.appendChild(container)

let child = document.createElement('div')
child.innerHTML = "aaa"
container.appendChild(child)

container.innerHTML += "<br>"
child.innerHTML = "bbb"